From Teratoma to Pacemaker: A Rare Case of Anti-N-Methyl-D-Aspartate Receptor (Anti-NMDAR) Encephalitis With Severe Autonomic Instability

We report a rare case of an 18-year-old female patient who presented with fever, altered mental status, and seizures and was diagnosed with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis in the setting of a right ovarian teratoma with high-titer antibodies. Despite immunotherapy and tumor resection, she developed severe autonomic instability characterized by recurrent bradycardia, sinus pauses, and an episode of asystole, necessitating temporary transvenous pacing followed by permanent pacemaker (Boston Scientific, USA) implantation. This case highlights the potential for life-threatening cardiac complications in anti-NMDAR encephalitis and emphasizes the need for continuous cardiac monitoring, timely intervention, and multidisciplinary management.